Portion of a headphone



FIG. 1 is a perspective of a portion of a headphone showing my new design;

FIG. 2 is an elevational view thereof;

FIG. 3 is a side elevational view, the opposite side being a mirror image thereof; and,

FIG. 4 is a top plan view, the bottom view being substantially a mirror image thereof.

The broken line showings of the three circles on the lower portion of the headphone and the clip are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a portion of a headphone, as shown and described. 